Quantitative measurements of structural changes resulting from ocular disease states may be helpful in the diagnosis and management of these conditions. In the normal state, cells are regularly arranged; diseases can change tissue surface texture. The application of speckle metrology to tissue texture characterization will be investigated. The aim of the proposed work is to use speckle measurements to quantitatively characterize the surface texture of ocular tissues and in particular, retinal and choroidal tissues. The following questions will be specifically addressed: l. Can speckle patterns be measured and analyzed from retinal and choroidal tissues? 2. Can instrumentation capable of measuring speckle patterns be developed for clinical use? 3. Are abnormal states in ocular tissues such as retinal pigment epithelium, nerve fiber layer, or retinal vessels able to be characterized using speckle patterns? Several already developed methods, experimental and analytical, will be applied to characterize tissue structure. From the results, specific methods for tissue characterization will be developed. Some of the methods to be applied are contrast measurements with a single laser; cross-correlation of speckle patterns formed with different wavelength light or with light incident at different angles; and two-dimensional Fourier analysis.